Heat sealing apparatus



Aug. 4, 1953 G. J. SELVIN HEAT SEALING APPARATUS 3 Sheets-Sheet 1 Filed July 25, 1950 INVENTOR. GERALD J SELVIN 8 1953 G. J. SELVIN HEAT SEALING APPARATUS 3 Sheets-Sheet 2 Filed July 25, 1950 INVENTOR. GERALD J. SELVIN Oh vm NM Om mm mm ON 2 m E w Filed July 25, 1950 1953 G. J. SELVIN 2,647,557

HEAT SEALING APPARATUS 3 Sheets-Sheet 3 JNVENTORQ GERALD J. SELVIN Patented Aug. 4, 1953 HEAT SEALING APPARATUS Gerald J. Selvin, Bronx, N. Y., assignor to the United States of America as represented by the United States Atomic Energy Commission Application July 25, 1950, Serial N 0. 175,804

4 Claims. 1

The present invention relates to a method and apparatus for sealing and cutting plastic tubing. In radiochemical laboratories it is often necessary to transfer radioactive fluids between various types of measuring, processing and storage apparatus. The material used for carrying these fluids must be resistant tocaustics, acids and some organic solvents. It must also be nonabsorptive. Tubing made of thermoplastic'material is commonly used as it can be manufactured with the desired properties and is sufficiently flexible for equipment coupling purposes. -When the equipment is disassembled or a leak develops in the system it is necessaryto remove or seal off the plastic tubing. As it would be a highly undesirable to leave open tubing through which the radioactive fluids could flow, this tubing must be either sealed or sealed and cut off. Also, since the radioactivity of the fluid might be of such an intensity that it Would-be dangerous for personnel to operate close t the tubing itis necessary that the device'for sealing the tubing be capable of operating at some distance therefrom. Any apparatus used must be highly mobile and maneuverable as the tubing to be sealed might be in a location inaccessible for employment of conventional heat sealing apparatus such as the commonly used relatively immobile clamps provided with heated jaws. The present invention provides a method and apparatus for carrying out these operations without the limitations imposed by the older conventional means heretofore used in this field.

It is accordingly an object of the present in vention to provide a new and improved remotely operated sealer for plastic tubing.

Another object is to provide a new and improved apparatus for both sealing and cutting plastic tubing in one peration.

A further object is to provide a new and improved apparatus for sealing and cutting thermoplastic material and adapted for remote manual operation while affording safety for an operator when handling toxic or radioactive materials.

More particularly, a, preferred embodiment of the invention consists of a support with a plurality of jaws mounted thereon. At least one of the jaws is movable with. respect to the others. Heating elements are associated with at least one of the jaws and means are provided for establishing relative movement between the jaws.

The many objects and advantages of the present invention may best be appreciated by reference to the accompanying drawings, the figures of which illustrate apparatus incorporating preferred embodiments of the present invention and capable of carrying out the method of the invention. p

In the drawings, Figure 1 is a perspective view of oneembodiment of the invention.

Figure 2 is a cross-sectional view ofthe apparatus takenalong the line 2-2 of Figure 1 with the plastic tubing shown in position for sealing.

Figure 3 is a transverse section through, the plastic tubing after it has been sealed.

Figure 4 is a transverse section throughthe plastic tubing after it has been scaled and cut.

Figure 5 is a perspective view of another embodiment of the apparatus of the invention.

Referring to Figures 1 and 2, one embodiment of the apparatus will be described. .A support It) is provided with upstanding jaws l2 and I4. Jaw I2 is aflixed to support l0 by means of screws i3 and is made up of a member [6, a heater block ll. made of heat resistant material, and a face plate 20. Contained within heater block I! are coils of electrical resistance wire [8. The heater coils are supported by insulating pins [9. Mounted on jaw I2 is a removable head containing a raised nib 24 in the central portion thereof. Head 22 is attached to jaw 12 when it is desired to out 01f the plastic tubing after it is sealed.

Jaw I4 is adapted to be moved with respect to support It) and consists of a face plate 28, a heater block 30 and a vertical member 32. Jaw l4 contains coils of resistance wire mounted on insulating pins arranged as in jaw I2. Movably attached at one end to jaw I4, as by a suitable bearing housing, is a remotely controlled jawactuatingv rod 34 which is threaded for a portion of its length. This portion is adapted to be threaded through a fixed nut 36 mounted in an upstanding member 38 which in turn is affixed to horizontal support [0 as by a screw 40. Surrounding rod 34 for part of its length is an elongated tube 42 serving the dual purpose of a bearing for the rod 34 and a housing for elecr trical leads. An adjustable handle 44, the significant function of which will later become apparent, is secured to rod 34 by means of an adjustable thumb screw 46. Also secured to rod 34 is a tube 48 towhich is attached a knurled adjusting wheel 50 and extending beyond which is mounted a rotatable sleeve 52, the handle 44, the wheel 50 and'the sleeve 52 all being adapted to cooperate in the manual supporting and manipulation-of the apparatus. In one convenient embodiment of the apparatus, for example, the

3 overall length of the support III was about six inches whereas the rod 34 was in excess of three feet. While the precise length of the rod 34 is in no way critical, it may however generally be described as being substantially longer than the remainder of the apparatus.

Electrical connections to the heater coils may be made by means of cable 54 which contains conductors 56 that are attached to terminals 58 mounted on member 32. Terminals 58 extend through member 32 and insulating block 30 to the heater coils. Cable 60 containing conductors 62 is connected to similar terminals mounted on vertical member I6. These terminals are connected to the heater coils of jaw I2. The main power cable 54 preferably enters and emerges through holes 64 and 66 respectively in tube 42 to prevent the cable from interfering with the actions of the operator.

The operation of the above-described apparatus will now be explained. When a leak occurs in the tubing or equipment is to be disassembled, the apparatus is brought to the proper location. The power cor-i154 is connected to a suitable power source. Sleeve 52 is held under one of the operators "arm's while handle '44 is gripped with the hand to providetheprop'er support, The jaws I2 and 14 are placed on opposite sides of the tubing I with support =I-0 beneath it as shown in Figure 2. Adjusting wheel 50 is rotated to move jaw '14 closer to jaw I2. This is continued until the walls of the plastic tubing are firmly compressed between the jaws. When the heating coils reach the proper temperature the thermoplastic tubing between the jaws will begin to melt and fuse. This is continued until all 'of the tubing "I0 between the jaws has fused and a good seal'is obtained. -If it is merely desired to seal thetubing, jaw I4 is moved away from jaw I2 and the operation is complete. For this purpose, movable head 2-2 would not have to be used and the sealing operation would be carried out between face plates 20 and 28 of j aws I-2and I4, respectively.

If it is desired to cut the tubing arter sealing, head 22 is slid on to jaw -I 2 before beginning the sealing operation. The procedure is their carried out as described above except that jaws I2 and I4 are brought closertogether after the tubing has been scaled, until the nib 24 parts the tubing. This results in two separate tubes each having one sealed end.

Figure 3 is a transverse'se'ctionbf the plastic tubing I0, after it has been sealed-showing the fused portion I2.

Figure 4 is a transverse section of the tubing after the fused portion I2 :h'asbeen cut by'nib -24, leaving two sealed ends 14 and 16.

Referring to Figure 5, a second embodiment'of the apparatus of the present invention is shown. This embodiment includes a fixed jaw -II0 mounted on a support consisting of two tubes I I2 and H4. Jaw H0 is made up of member I I6, heater block H8 and faceplate I 20. Internally, jaw H0 is constructed similarly to fixed jaw I2 described in Figure 1. g

In the central portion of fa'c'e plate I20 is a raised nib I22. The nib'isn'ot part :cr plate I20 but is meshed with that platein a conventional dovetail arrangement. Nib I22 is usedw'he'n it is desired to cut the plastic time after sealing. If it is merely desired to seal the'tubing,'the-'nib can be slid out from plate I20'a'nd'replaced bya dovetailed insert which is flush "with the faoe of plate I20.

Confronting jaw I I0 is a movable jaw I24. The movable jaw is made up of member I26, heater block I28 and face plate I30.

Tubes H2 and H4 each have one end attached to member II6. These tubes extend through holes I32 and I34, respectively, in jaw I24, and are connected at their other end by cross piece 136.

Attachedto jaw I24 is a rod I38 which extends through hole I40 in member II6. Rod I38 is surrounded for part of its length by tube I42. One end of tube I42 is mounted in vertical member 'I'I6. In the periphery of tube I42 are two slots I44 (only one is shown) through which a dowel pin I46 is attached to rod I38. The ends of dowel pin I46 are mounted in a movable handle I50. A fixed handle I52 is mounted on tube I42 by means of dowel pin I 54.

Attached to the underside of tube I42 is a rack I56. A trigger ratchet I58 is meshed with rack I56 and is supported in movable handle I50 by dowel pin I60. As indicated by the drawing, rack I56 is spaced a substantial distance from member Il6 so that the operator may be protected from the contents of the-tube to be sealed, as for example from theradioactivity of the fluid carried in such tubing.

Electrical power is supplied to the heating coils of the apparatus by means of cable I62. This cable is carried inside of tube I42 and emerges close to member I I6 through hole I64. The cable contains conductors 166 which are connected to terminals (notshown) on mem'ber 'I I6. The terminals extend through member I I6 and heater block II8 to the heating coils in :jaw 110. Also connected to the terminals on member I16 are conductors I68. These conductors extend'throu'gh tubes I I2'and H4 and emerge-through holes I10 and 112, respectively. Conductors I68 are -con nected to terminals I14 to supply power to the heating coils in jaw I24. Since the electrical connections are made in this manner, there "is no possibility of having the conductors interfere with the'operation of the apparatus.

The operation of this embodiment of the apparatus will now be described. The device is placed-so that the thermoplastic tubing is located between jaws I I0 and I24 above tubes I I2 and -I I4. The rearward extension of tube I42 is placed under the-operator's arm while handle I52 is held "firmly in one hand. Handle I50 is held in the other hand and may be moved towards handle I52 by depressing trigger ratchet I58 which disengages the handle from rack I56. This causes jaw I24 :to move towards jaw H0 along tubes I I2 and I24 by meansofthe connecting member I38. When the desired pressure on the plastic tubing is obtained, the trigger ratchet I58 is released and the heating coils in the .jaws I I0 and I24 are energized :to perform thesealing operation as described-above. After the operation is complete, the trigger ratchet I58 is depressed and handle -I50 is moved away from handle I52. As mentioned-above, this "embodimentmay'be used forsealing-orcutting, depending on the dovetailed insert I22 :used in face plate -I-20.

lt isapparentthat theappa'ratus of thepresent invention is particularly well adapted for its .purpose 'inview of its simplicity, lightweight and arrangement of manually operated portions. -It may be 'easilypperated at a safe' -distance :trom the source of radioactivity. It can be-held and used at-any angle and can reach into small areas that might otherwise -be inaccessible. A great need exists for such a highly mobile and maneuverable apparatus as a short time delay in stopping a leak in a radioactive system may lead to serious consequences.

Since many embodiments of the present invention might be made and since many other changes may be made in the preferred embodiments described above, it is to be understood that the foregoing description is to be interpreted as illustrative only and not in a limiting sense except as required by the appended claims.

I claim:

1. Heat sealing apparatus adapted for remote manual operation which 1 comprises a support member for an articleto be sealed, a plurality of jaws mounted on said support, at least one of said jaws being movable with respect to the others and to said article, means for heating at least one of said jaws, manual actuating means for said movable jaw disposed at a substantial distance therefrom and connected thereto by an elongated rod and a handle affixed to said rod closer to said actuating means than to said support, said handle being adapted for the manual holding of said apparatus during the sealing operation.

2. Heat sealing apparatus adapted for remote manual operation which comprises a support member for an article to be sealed, a pair of jaws mounted on said support having plane parallel confronting faces, at least one of said jaws being movable with respect to the other and to said article, means for heating at least one of said jaws, manual actuating means iorsaid movable jaw disposed at a substantial distance therefrom and connected thereto by an elongated rod and a handle affixed to said rod closer to said actuating means than to said support, said handle being adapted for the manual holding of said apparatus during the sealing operation.

3. Heat sealing apparatus adapted for remote manual operation which comprises a support member for an article to be sealed, a pair of jaws mounted on said support having plane parallel confronting faces, at least one of said jaws being movable with respect to the other and to said article, means for heating at least one of said jaws, an elongated rotatable rod operatively associated with said movable jaw, a manually adjustable wheel aflixed to said rotatable rod at a substantial distance from said jaw whereby rotation of said rod moves said movable jaw towards or away from said other jaw and a handle aiiixed to said rod closer to said wheel than to said jaw, said handle being adapted for the manual holding of said apparatus during the sealing operation.

4. Heat sealing apparatus adapted for remote manual operation which comprises a support member for an article to be sealed, a pair of jaws mounted on said support, said jaws having a pair of plane parallel confronting faces, at least one of said jaws being movable with respect to the other and to said article, means for heating at least one of said jaws, an elongated rod affixed to said movable jaw, a tubular member surrounding said rod for part of its length and containing a rack along the surface thereof, a first handle afiixed to said rod at a substantial distance from said support and containing a trigger ratchet operatively associated with said rack and a second handle afi'ixed to said tubular member whereby said movable jaw may be moved towards or away from said other jaw by depressing said trigger ratchet and moving said first handle along said tubular member.

GERALD J. SELVIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,630,990 Wagg May 31, 1927 1,875,975 Alm Sept. 6, 1932 1,997,268 Scharpf Apr. 9, 1935 2,150,464 Smith Mar. 14, 1939 2,443,749 Stunkel June 22, 1948 2,514,197 Grosen et a1 July 4, 1950 2,542,629 Clawson Feb. 20, 1951 

